Disconnect the battery and do not reconnect until you have reconnected everything properly, this will stop the bag going off and the will stop the airbag light from coming on.
There should be 2 screws on the back of the steering wheel, this will bring the front of the wheel off. Remove and unplug the airbag module carefully (wear gloves and keep your face away from the device), remove the large nut from the centre of the wheel and pull the whole assembly off.
Im not sure if you need to remove the wheel though do you? I thought everything could be accessed from the fairing under the wheel.
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Evil-Punto AKA Evilution.